Schulz U G R, Briley D, Meagher T, Molyneux A, Rothwell P M
Stroke Prevention Research Unit, Department of Clinical Neurology, Radcliffe Infirmary, Oxford, UK.
J Neurol Neurosurg Psychiatry. 2003 Jun;74(6):734-8. doi: 10.1136/jnnp.74.6.734.
Diffusion weighted brain imaging (DWI) is used in acute stroke, and also shows an acute ischaemic lesion in most transient ischamic attack (TIA) patients scanned acutely. However, it may also be useful in identifying subacute ischaemic lesions in patients with minor stroke or TIA who present several weeks after symptom onset. This study investigated the sensitivity and the observer reproducibility of DWI in cerebral TIA and minor ischaemic stroke patients scanned more than two weeks after the last symptomatic event.
Consecutive patients underwent magnetic resonance imaging (T2, DWI, ADC). The presence of clinically appropriate lesions was assessed by two independent observers, and related to the type of presenting event, the NIH score, persistence of symptoms and signs, and the time since the presenting event.
101 patients (53 men) were scanned at a median time of 21 days (IQR=17-28) after symptom onset. Reproducibility of the assessment of DWI abnormalities was high: interobserver agreement =97% (kappa=0.94, p<0.0001); intraobserver agreement =94% (kappa=0.88, p<0.0001). DWI showed a clinically appropriate ischaemic lesion in 29 of 51 (57%) minor stroke patients, and in 7 of 50 (14%) TIA patients. The independent predictors of a positive DWI scan were presentation with minor stroke versus TIA (p=0.009) and increasing NIH score (p=0.009), but there was no difference between patients presenting 2-4 weeks compared with >4 weeks after symptom onset. In minor stroke patients, the presence of a clinically appropriate lesion was associated with persistent symptoms (63% versus 36%; p=0.12) and signs (64% versus 33%, p=0.06) at the time of scanning.
DWI shows a clinically appropriate ischaemic lesion in more than half of minor stroke patients presenting more than two weeks after the symptomatic event, but only in a small proportion of patients with TIA. The persistence of lesions on DWI is closely related to markers of severity of the ischaemic event. These results justify larger studies of the clinical usefulness of DWI in subacute minor stroke.
扩散加权脑成像（DWI）用于急性卒中，并且在大多数急性扫描的短暂性脑缺血发作（TIA）患者中也显示出急性缺血性病变。然而，它对于识别症状发作数周后出现的轻度卒中和TIA患者的亚急性缺血性病变可能也有用。本研究调查了DWI在最后一次症状发作两周多后扫描的脑TIA和轻度缺血性卒中患者中的敏感性和观察者可重复性。
连续的患者接受磁共振成像（T2、DWI、ADC）检查。由两名独立观察者评估临床上合适病变的存在情况，并将其与就诊事件类型、美国国立卫生研究院（NIH）评分、症状和体征的持续时间以及自就诊事件以来的时间相关联。
101例患者（53例男性）在症状发作后的中位时间21天（四分位间距=17 - 28天）接受扫描。DWI异常评估的可重复性很高：观察者间一致性=97%（kappa=0.94，p<0.0001）；观察者内一致性=94%（kappa=0.88，p<0.0001）。在51例轻度卒中患者中的29例（57%）以及50例TIA患者中的7例（14%）中，DWI显示出临床上合适的缺血性病变。DWI扫描阳性的独立预测因素是轻度卒中与TIA的就诊情况（p=0.009）以及NIH评分增加（p=0.009），但症状发作后2 - 4周就诊的患者与>4周就诊的患者之间无差异。在轻度卒中患者中，临床上合适病变的存在与扫描时症状持续存在（63%对36%；p=0.12）和体征持续存在（64%对33%，p=0.06）相关。
DWI在症状性事件两周多后出现的超过一半的轻度卒中患者中显示出临床上合适的缺血性病变，但在TIA患者中只有一小部分出现。DWI上病变的持续存在与缺血事件严重程度的标志物密切相关。这些结果证明有必要对DWI在亚急性轻度卒中中的临床实用性进行更大规模的研究。
